Coated metal sheets, excellent in versatility, designability, durability and the like, have been used in various applications. In coated metal sheets for exterior building material applications, mainly from the viewpoint of designability, a gloss adjusting agent is usually blended in an overcoat coating film on the surface of the coated metal sheet. Silica is usually used as the gloss adjusting agent in the coated metal sheets for exterior building materials. The particle diameter of the silica is usually specified by an average particle diameter. The average particle diameter of the silica as the gloss adjusting agent in the coated metal sheet is usually from 3 to 30 μm, depending on the color and the application (for example, see PTL 1 (paragraph 0018)).